Journal
JOURNAL OF BACTERIOLOGY
Volume 193, Issue 7, Pages 1653-1662Publisher
AMER SOC MICROBIOLOGY
DOI: 10.1128/JB.01310-10
Keywords
-
Categories
Funding
- AFOSR [FA95500710158]
- NIH [P50GM076547, 1R01GM077398-01A2]
- Office of Biological and Environmental Research of the Office of Science, U.S. Department of Energy [DE-AC02-05CH11231]
- Maryland Cigarette Restitution Fund
- NIEHS Center [P30 ES00319]
Ask authors/readers for more resources
Oxidative stress occurs when the generation of reactive oxygen species (ROS) exceeds the capacity of the cell's endogenous systems to neutralize them. Our analyses of the cellular damage and oxidative stress responses of the archaeon Halobacterium salinarum exposed to ionizing radiation (IR) revealed a critical role played by nonenzymatic antioxidant processes in the resistance of H. salinarum to IR. ROS-scavenging enzymes were essential for resistance to chemical oxidants, yet those enzymes were not necessary for H. salinarum's resistance to IR. We found that protein-free cell extracts from H. salinarum provided a high level of protection for protein activity against IR in vitro but did not protect DNA significantly. Compared with cell extracts of radiation-sensitive bacteria, H. salinarum extracts were enriched in manganese, amino acids, and peptides, supporting an essential role in ROS scavenging for those small molecules in vivo. With regard to chemical oxidants, we showed that the damage caused by gamma irradiation was mechanistically different than that produced by hydrogen peroxide or by the superoxide-generating redox-cycling drug paraquat. The data presented support the idea that IR resistance is most likely achieved by a metabolic route, with a combination of tightly coordinated physiological processes.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available